// SPDX-License-Identifier: GPL-2.0-only/* * AppArmor security module * * This file contains AppArmor label definitions * * Copyright 2017 Canonical Ltd. */ #include <linux/audit.h>#include <linux/seq_file.h>#include <linux/sort.h> #include "include/apparmor.h"#include "include/cred.h"#include "include/label.h"#include "include/policy.h"#include "include/secid.h" /* * the aa_label represents the set of profiles confining an object * * Labels maintain a reference count to the set of pointers they reference * Labels are ref counted by * tasks and object via the security field/security context off the field * code - will take a ref count on a label if it needs the label * beyond what is possible with an rcu_read_lock. * profiles - each profile is a label * secids - a pinned secid will keep a refcount of the label it is * referencing * objects - inode, files, sockets, ... * * Labels are not ref counted by the label set, so they maybe removed and * freed when no longer in use. * */ #define PROXY_POISON 97#define LABEL_POISON 100 static void free_proxy(struct aa_proxy *proxy){ if (proxy) { /* p->label will not updated any more as p is dead */ aa_put_label(rcu_dereference_protected(proxy->label, true)); memset(proxy, 0, sizeof(*proxy)); RCU_INIT_POINTER(proxy->label, (struct aa_label *)PROXY_POISON); kfree(proxy); }} void aa_proxy_kref(struct kref *kref){ struct aa_proxy *proxy = container_of(kref, struct aa_proxy, count); free_proxy(proxy);} struct aa_proxy *aa_alloc_proxy(struct aa_label *label, gfp_t gfp){ struct aa_proxy *new; new = kzalloc(sizeof(struct aa_proxy), gfp); if (new) { kref_init(&new->count); rcu_assign_pointer(new->label, aa_get_label(label)); } return new;} /* requires profile list write lock held */void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new){ struct aa_label *tmp; AA_BUG(!orig); AA_BUG(!new); lockdep_assert_held_write(&labels_set(orig)->lock); tmp = rcu_dereference_protected(orig->proxy->label, &labels_ns(orig)->lock); rcu_assign_pointer(orig->proxy->label, aa_get_label(new)); orig->flags |= FLAG_STALE; aa_put_label(tmp);} static void __proxy_share(struct aa_label *old, struct aa_label *new){ struct aa_proxy *proxy = new->proxy; new->proxy = aa_get_proxy(old->proxy); __aa_proxy_redirect(old, new); aa_put_proxy(proxy);} /** * ns_cmp - compare ns for label set ordering * @a: ns to compare (NOT NULL) * @b: ns to compare (NOT NULL) * * Returns: <0 if a < b * ==0 if a == b * >0 if a > b */static int ns_cmp(struct aa_ns *a, struct aa_ns *b){ int res; AA_BUG(!a); AA_BUG(!b); AA_BUG(!a->base.hname); AA_BUG(!b->base.hname); if (a == b) return 0; res = a->level - b->level; if (res) return res; return strcmp(a->base.hname, b->base.hname);} /** * profile_cmp - profile comparison for set ordering * @a: profile to compare (NOT NULL) * @b: profile to compare (NOT NULL) * * Returns: <0 if a < b * ==0 if a == b * >0 if a > b */static int profile_cmp(struct aa_profile *a, struct aa_profile *b){ int res; AA_BUG(!a); AA_BUG(!b); AA_BUG(!a->ns); AA_BUG(!b->ns); AA_BUG(!a->base.hname); AA_BUG(!b->base.hname); if (a == b || a->base.hname == b->base.hname) return 0; res = ns_cmp(a->ns, b->ns); if (res) return res; return strcmp(a->base.hname, b->base.hname);} /** * vec_cmp - label comparison for set ordering * @a: label to compare (NOT NULL) * @vec: vector of profiles to compare (NOT NULL) * @n: length of @vec * * Returns: <0 if a < vec * ==0 if a == vec * >0 if a > vec */static int vec_cmp(struct aa_profile **a, int an, struct aa_profile **b, int bn){ int i; AA_BUG(!a); AA_BUG(!*a); AA_BUG(!b); AA_BUG(!*b); AA_BUG(an <= 0); AA_BUG(bn <= 0); for (i = 0; i < an && i < bn; i++) { int res = profile_cmp(a[i], b[i]); if (res != 0) return res; } return an - bn;} static bool vec_is_stale(struct aa_profile **vec, int n){ int i; AA_BUG(!vec); for (i = 0; i < n; i++) { if (profile_is_stale(vec[i])) return true; } return false;} static bool vec_unconfined(struct aa_profile **vec, int n){ int i; AA_BUG(!vec); for (i = 0; i < n; i++) { if (!profile_unconfined(vec[i])) return false; } return true;} static int sort_cmp(const void *a, const void *b){ return profile_cmp(*(struct aa_profile **)a, *(struct aa_profile **)b);} /* * assumes vec is sorted * Assumes @vec has null terminator at vec[n], and will null terminate * vec[n - dups] */static inline int unique(struct aa_profile **vec, int n){ int i, pos, dups = 0; AA_BUG(n < 1); AA_BUG(!vec); pos = 0; for (i = 1; i < n; i++) { int res = profile_cmp(vec[pos], vec[i]); AA_BUG(res > 0, "vec not sorted"); if (res == 0) { /* drop duplicate */ aa_put_profile(vec[i]); dups++; continue; } pos++; if (dups) vec[pos] = vec[i]; } AA_BUG(dups < 0); return dups;} /** * aa_vec_unique - canonical sort and unique a list of profiles * @n: number of refcounted profiles in the list (@n > 0) * @vec: list of profiles to sort and merge * * Returns: the number of duplicates eliminated == references put * * If @flags & VEC_FLAG_TERMINATE @vec has null terminator at vec[n], and will * null terminate vec[n - dups] */int aa_vec_unique(struct aa_profile **vec, int n, int flags){ int i, dups = 0; AA_BUG(n < 1); AA_BUG(!vec); /* vecs are usually small and inorder, have a fallback for larger */ if (n > 8) { sort(vec, n, sizeof(struct aa_profile *), sort_cmp, NULL); dups = unique(vec, n); goto out; } /* insertion sort + unique in one */ for (i = 1; i < n; i++) { struct aa_profile *tmp = vec[i]; int pos, j; for (pos = i - 1 - dups; pos >= 0; pos--) { int res = profile_cmp(vec[pos], tmp); if (res == 0) { /* drop duplicate entry */ aa_put_profile(tmp); dups++; goto continue_outer; } else if (res < 0) break; } /* pos is at entry < tmp, or index -1. Set to insert pos */ pos++; for (j = i - dups; j > pos; j--) vec[j] = vec[j - 1]; vec[pos] = tmp;continue_outer: ; } AA_BUG(dups < 0); out: if (flags & VEC_FLAG_TERMINATE) vec[n - dups] = NULL; return dups;} void aa_label_destroy(struct aa_label *label){ AA_BUG(!label); if (!label_isprofile(label)) { struct aa_profile *profile; struct label_it i; aa_put_str(label->hname); label_for_each(i, label, profile) { aa_put_profile(profile); label->vec[i.i] = (struct aa_profile *) (LABEL_POISON + (long) i.i); } } if (label->proxy) { if (rcu_dereference_protected(label->proxy->label, true) == label) rcu_assign_pointer(label->proxy->label, NULL); aa_put_proxy(label->proxy); } aa_free_secid(label->secid); label->proxy = (struct aa_proxy *) PROXY_POISON + 1;} void aa_label_free(struct aa_label *label){ if (!label) return; aa_label_destroy(label); kfree(label);} static void label_free_switch(struct aa_label *label){ if (label->flags & FLAG_NS_COUNT) aa_free_ns(labels_ns(label)); else if (label_isprofile(label)) aa_free_profile(labels_profile(label)); else aa_label_free(label);} static void label_free_rcu(struct rcu_head *head){ struct aa_label *label = container_of(head, struct aa_label, rcu); if (label->flags & FLAG_IN_TREE) (void) aa_label_remove(label); label_free_switch(label);} void aa_label_kref(struct kref *kref){ struct aa_label *label = container_of(kref, struct aa_label, count); struct aa_ns *ns = labels_ns(label); if (!ns) { /* never live, no rcu callback needed, just using the fn */ label_free_switch(label); return; } /* TODO: update labels_profile macro so it works here */ AA_BUG(label_isprofile(label) && on_list_rcu(&label->vec[0]->base.profiles)); AA_BUG(label_isprofile(label) && on_list_rcu(&label->vec[0]->base.list)); /* TODO: if compound label and not stale add to reclaim cache */ call_rcu(&label->rcu, label_free_rcu);} static void label_free_or_put_new(struct aa_label *label, struct aa_label *new){ if (label != new) /* need to free directly to break circular ref with proxy */ aa_label_free(new); else aa_put_label(new);} bool aa_label_init(struct aa_label *label, int size, gfp_t gfp){ AA_BUG(!label); AA_BUG(size < 1); if (aa_alloc_secid(label, gfp) < 0) return false; label->size = size; /* doesn't include null */ label->vec[size] = NULL; /* null terminate */ kref_init(&label->count); RB_CLEAR_NODE(&label->node); return true;} /** * aa_label_alloc - allocate a label with a profile vector of @size length * @size: size of profile vector in the label * @proxy: proxy to use OR null if to allocate a new one * @gfp: memory allocation type * * Returns: new label * else NULL if failed */struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp){ struct aa_label *new; AA_BUG(size < 1); /* + 1 for null terminator entry on vec */ new = kzalloc(sizeof(*new) + sizeof(struct aa_profile *) * (size + 1), gfp); AA_DEBUG("%s (%p)\n", __func__, new); if (!new) goto fail; if (!aa_label_init(new, size, gfp)) goto fail; if (!proxy) { proxy = aa_alloc_proxy(new, gfp); if (!proxy) goto fail; } else aa_get_proxy(proxy); /* just set new's proxy, don't redirect proxy here if it was passed in*/ new->proxy = proxy; return new; fail: kfree(new); return NULL;} /** * label_cmp - label comparison for set ordering * @a: label to compare (NOT NULL) * @b: label to compare (NOT NULL) * * Returns: <0 if a < b * ==0 if a == b * >0 if a > b */static int label_cmp(struct aa_label *a, struct aa_label *b){ AA_BUG(!b); if (a == b) return 0; return vec_cmp(a->vec, a->size, b->vec, b->size);} /* helper fn for label_for_each_confined */int aa_label_next_confined(struct aa_label *label, int i){ AA_BUG(!label); AA_BUG(i < 0); for (; i < label->size; i++) { if (!profile_unconfined(label->vec[i])) return i; } return i;} /** * aa_label_next_not_in_set - return the next profile of @sub not in @set * @I: label iterator * @set: label to test against * @sub: label to if is subset of @set * * Returns: profile in @sub that is not in @set, with iterator set pos after * else NULL if @sub is a subset of @set */struct aa_profile *__aa_label_next_not_in_set(struct label_it *I, struct aa_label *set, struct aa_label *sub){Lines 1–500 of 2161. 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// SPDX-License-Identifier: GPL-2.0-only /* * AppArmor security module * * This file contains AppArmor label definitions * * Copyright 2017 Canonical Ltd. */ #include <linux/audit.h> #include <linux/seq_file.h> #include <linux/sort.h> #include "include/apparmor.h" #include "include/cred.h" #include "include/label.h" #include "include/policy.h" #include "include/secid.h" /* * the aa_label represents the set of profiles confining an object * * Labels maintain a reference count to the set of pointers they reference * Labels are ref counted by * tasks and object via the security field/security context off the field * code - will take a ref count on a label if it needs the label * beyond what is possible with an rcu_read_lock. * profiles - each profile is a label * secids - a pinned secid will keep a refcount of the label it is * referencing * objects - inode, files, sockets, ... * * Labels are not ref counted by the label set, so they maybe removed and * freed when no longer in use. * */ #define PROXY_POISON 97 #define LABEL_POISON 100 static void free_proxy(struct aa_proxy *proxy) { if (proxy) { /* p->label will not updated any more as p is dead */ aa_put_label(rcu_dereference_protected(proxy->label, true)); memset(proxy, 0, sizeof(*proxy)); RCU_INIT_POINTER(proxy->label, (struct aa_label *)PROXY_POISON); kfree(proxy); } } void aa_proxy_kref(struct kref *kref) { struct aa_proxy *proxy = container_of(kref, struct aa_proxy, count); free_proxy(proxy); } struct aa_proxy *aa_alloc_proxy(struct aa_label *label, gfp_t gfp) { struct aa_proxy *new; new = kzalloc(sizeof(struct aa_proxy), gfp); if (new) { kref_init(&new->count); rcu_assign_pointer(new->label, aa_get_label(label)); } return new; } /* requires profile list write lock held */ void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new) { struct aa_label *tmp; AA_BUG(!orig); AA_BUG(!new); lockdep_assert_held_write(&labels_set(orig)->lock); tmp = rcu_dereference_protected(orig->proxy->label, &labels_ns(orig)->lock); rcu_assign_pointer(orig->proxy->label, aa_get_label(new)); orig->flags |= FLAG_STALE; aa_put_label(tmp); } static void __proxy_share(struct aa_label *old, struct aa_label *new) { struct aa_proxy *proxy = new->proxy; new->proxy = aa_get_proxy(old->proxy); __aa_proxy_redirect(old, new); aa_put_proxy(proxy); } /** * ns_cmp - compare ns for label set ordering * @a: ns to compare (NOT NULL) * @b: ns to compare (NOT NULL) * * Returns: <0 if a < b * ==0 if a == b * >0 if a > b */ static int ns_cmp(struct aa_ns *a, struct aa_ns *b) { int res; AA_BUG(!a); AA_BUG(!b); AA_BUG(!a->base.hname); AA_BUG(!b->base.hname); if (a == b) return 0; res = a->level - b->level; if (res) return res; return strcmp(a->base.hname, b->base.hname); } /** * profile_cmp - profile comparison for set ordering * @a: profile to compare (NOT NULL) * @b: profile to compare (NOT NULL) * * Returns: <0 if a < b * ==0 if a == b * >0 if a > b */ static int profile_cmp(struct aa_profile *a, struct aa_profile *b) { int res; AA_BUG(!a); AA_BUG(!b); AA_BUG(!a->ns); AA_BUG(!b->ns); AA_BUG(!a->base.hname); AA_BUG(!b->base.hname); if (a == b || a->base.hname == b->base.hname) return 0; res = ns_cmp(a->ns, b->ns); if (res) return res; return strcmp(a->base.hname, b->base.hname); } /** * vec_cmp - label comparison for set ordering * @a: label to compare (NOT NULL) * @vec: vector of profiles to compare (NOT NULL) * @n: length of @vec * * Returns: <0 if a < vec * ==0 if a == vec * >0 if a > vec */ static int vec_cmp(struct aa_profile **a, int an, struct aa_profile **b, int bn) { int i; AA_BUG(!a); AA_BUG(!*a); AA_BUG(!b); AA_BUG(!*b); AA_BUG(an <= 0); AA_BUG(bn <= 0); for (i = 0; i < an && i < bn; i++) { int res = profile_cmp(a[i], b[i]); if (res != 0) return res; } return an - bn; } static bool vec_is_stale(struct aa_profile **vec, int n) { int i; AA_BUG(!vec); for (i = 0; i < n; i++) { if (profile_is_stale(vec[i])) return true; } return false; } static bool vec_unconfined(struct aa_profile **vec, int n) { int i; AA_BUG(!vec); for (i = 0; i < n; i++) { if (!profile_unconfined(vec[i])) return false; } return true; } static int sort_cmp(const void *a, const void *b) { return profile_cmp(*(struct aa_profile **)a, *(struct aa_profile **)b); } /* * assumes vec is sorted * Assumes @vec has null terminator at vec[n], and will null terminate * vec[n - dups] */ static inline int unique(struct aa_profile **vec, int n) { int i, pos, dups = 0; AA_BUG(n < 1); AA_BUG(!vec); pos = 0; for (i = 1; i < n; i++) { int res = profile_cmp(vec[pos], vec[i]); AA_BUG(res > 0, "vec not sorted"); if (res == 0) { /* drop duplicate */ aa_put_profile(vec[i]); dups++; continue; } pos++; if (dups) vec[pos] = vec[i]; } AA_BUG(dups < 0); return dups; } /** * aa_vec_unique - canonical sort and unique a list of profiles * @n: number of refcounted profiles in the list (@n > 0) * @vec: list of profiles to sort and merge * * Returns: the number of duplicates eliminated == references put * * If @flags & VEC_FLAG_TERMINATE @vec has null terminator at vec[n], and will * null terminate vec[n - dups] */ int aa_vec_unique(struct aa_profile **vec, int n, int flags) { int i, dups = 0; AA_BUG(n < 1); AA_BUG(!vec); /* vecs are usually small and inorder, have a fallback for larger */ if (n > 8) { sort(vec, n, sizeof(struct aa_profile *), sort_cmp, NULL); dups = unique(vec, n); goto out; } /* insertion sort + unique in one */ for (i = 1; i < n; i++) { struct aa_profile *tmp = vec[i]; int pos, j; for (pos = i - 1 - dups; pos >= 0; pos--) { int res = profile_cmp(vec[pos], tmp); if (res == 0) { /* drop duplicate entry */ aa_put_profile(tmp); dups++; goto continue_outer; } else if (res < 0) break; } /* pos is at entry < tmp, or index -1. Set to insert pos */ pos++; for (j = i - dups; j > pos; j--) vec[j] = vec[j - 1]; vec[pos] = tmp; continue_outer: ; } AA_BUG(dups < 0); out: if (flags & VEC_FLAG_TERMINATE) vec[n - dups] = NULL; return dups; } void aa_label_destroy(struct aa_label *label) { AA_BUG(!label); if (!label_isprofile(label)) { struct aa_profile *profile; struct label_it i; aa_put_str(label->hname); label_for_each(i, label, profile) { aa_put_profile(profile); label->vec[i.i] = (struct aa_profile *) (LABEL_POISON + (long) i.i); } } if (label->proxy) { if (rcu_dereference_protected(label->proxy->label, true) == label) rcu_assign_pointer(label->proxy->label, NULL); aa_put_proxy(label->proxy); } aa_free_secid(label->secid); label->proxy = (struct aa_proxy *) PROXY_POISON + 1; } void aa_label_free(struct aa_label *label) { if (!label) return; aa_label_destroy(label); kfree(label); } static void label_free_switch(struct aa_label *label) { if (label->flags & FLAG_NS_COUNT) aa_free_ns(labels_ns(label)); else if (label_isprofile(label)) aa_free_profile(labels_profile(label)); else aa_label_free(label); } static void label_free_rcu(struct rcu_head *head) { struct aa_label *label = container_of(head, struct aa_label, rcu); if (label->flags & FLAG_IN_TREE) (void) aa_label_remove(label); label_free_switch(label); } void aa_label_kref(struct kref *kref) { struct aa_label *label = container_of(kref, struct aa_label, count); struct aa_ns *ns = labels_ns(label); if (!ns) { /* never live, no rcu callback needed, just using the fn */ label_free_switch(label); return; } /* TODO: update labels_profile macro so it works here */ AA_BUG(label_isprofile(label) && on_list_rcu(&label->vec[0]->base.profiles)); AA_BUG(label_isprofile(label) && on_list_rcu(&label->vec[0]->base.list)); /* TODO: if compound label and not stale add to reclaim cache */ call_rcu(&label->rcu, label_free_rcu); } static void label_free_or_put_new(struct aa_label *label, struct aa_label *new) { if (label != new) /* need to free directly to break circular ref with proxy */ aa_label_free(new); else aa_put_label(new); } bool aa_label_init(struct aa_label *label, int size, gfp_t gfp) { AA_BUG(!label); AA_BUG(size < 1); if (aa_alloc_secid(label, gfp) < 0) return false; label->size = size; /* doesn't include null */ label->vec[size] = NULL; /* null terminate */ kref_init(&label->count); RB_CLEAR_NODE(&label->node); return true; } /** * aa_label_alloc - allocate a label with a profile vector of @size length * @size: size of profile vector in the label * @proxy: proxy to use OR null if to allocate a new one * @gfp: memory allocation type * * Returns: new label * else NULL if failed */ struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp) { struct aa_label *new; AA_BUG(size < 1); /* + 1 for null terminator entry on vec */ new = kzalloc(sizeof(*new) + sizeof(struct aa_profile *) * (size + 1), gfp); AA_DEBUG("%s (%p)\n", __func__, new); if (!new) goto fail; if (!aa_label_init(new, size, gfp)) goto fail; if (!proxy) { proxy = aa_alloc_proxy(new, gfp); if (!proxy) goto fail; } else aa_get_proxy(proxy); /* just set new's proxy, don't redirect proxy here if it was passed in*/ new->proxy = proxy; return new; fail: kfree(new); return NULL; } /** * label_cmp - label comparison for set ordering * @a: label to compare (NOT NULL) * @b: label to compare (NOT NULL) * * Returns: <0 if a < b * ==0 if a == b * >0 if a > b */ static int label_cmp(struct aa_label *a, struct aa_label *b) { AA_BUG(!b); if (a == b) return 0; return vec_cmp(a->vec, a->size, b->vec, b->size); } /* helper fn for label_for_each_confined */ int aa_label_next_confined(struct aa_label *label, int i) { AA_BUG(!label); AA_BUG(i < 0); for (; i < label->size; i++) { if (!profile_unconfined(label->vec[i])) return i; } return i; } /** * aa_label_next_not_in_set - return the next profile of @sub not in @set * @I: label iterator * @set: label to test against * @sub: label to if is subset of @set * * Returns: profile in @sub that is not in @set, with iterator set pos after * else NULL if @sub is a subset of @set */ struct aa_profile *__aa_label_next_not_in_set(struct label_it *I, struct aa_label *set, struct aa_label *sub) {